String.Normalize Method

Reference

Definition

Namespace:: System

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Returns a new string whose binary representation is in a particular Unicode normalization form.

Overloads

Normalize()	Returns a new string whose textual value is the same as this string, but whose binary representation is in Unicode normalization form C.
Normalize(NormalizationForm)	Returns a new string whose textual value is the same as this string, but whose binary representation is in the specified Unicode normalization form.

Examples

The following example normalizes a string to each of four normalization forms, confirms the string was normalized to the specified normalization form, then lists the code points in the normalized string.

using namespace System;
using namespace System::Text;

void Show( String^ title, String^ s )
{
   Console::Write( "Characters in string {0} = ", title );
   for each (short x in s) {
      Console::Write("{0:X4} ", x);
   }
   Console::WriteLine();
}

int main()
{
   
   // Character c; combining characters acute and cedilla; character 3/4
   array<Char>^temp0 = {L'c',L'\u0301',L'\u0327',L'\u00BE'};
   String^ s1 = gcnew String( temp0 );
   String^ s2 = nullptr;
   String^ divider = gcnew String( '-',80 );
   divider = String::Concat( Environment::NewLine, divider, Environment::NewLine );

   Show( "s1", s1 );
   Console::WriteLine();
   Console::WriteLine( "U+0063 = LATIN SMALL LETTER C" );
   Console::WriteLine( "U+0301 = COMBINING ACUTE ACCENT" );
   Console::WriteLine( "U+0327 = COMBINING CEDILLA" );
   Console::WriteLine( "U+00BE = VULGAR FRACTION THREE QUARTERS" );
   Console::WriteLine( divider );
   Console::WriteLine( "A1) Is s1 normalized to the default form (Form C)?: {0}", s1->IsNormalized() );
   Console::WriteLine( "A2) Is s1 normalized to Form C?:  {0}", s1->IsNormalized( NormalizationForm::FormC ) );
   Console::WriteLine( "A3) Is s1 normalized to Form D?:  {0}", s1->IsNormalized( NormalizationForm::FormD ) );
   Console::WriteLine( "A4) Is s1 normalized to Form KC?: {0}", s1->IsNormalized( NormalizationForm::FormKC ) );
   Console::WriteLine( "A5) Is s1 normalized to Form KD?: {0}", s1->IsNormalized( NormalizationForm::FormKD ) );
   Console::WriteLine( divider );
   Console::WriteLine( "Set string s2 to each normalized form of string s1." );
   Console::WriteLine();
   Console::WriteLine( "U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE" );
   Console::WriteLine( "U+0033 = DIGIT THREE" );
   Console::WriteLine( "U+2044 = FRACTION SLASH" );
   Console::WriteLine( "U+0034 = DIGIT FOUR" );
   Console::WriteLine( divider );
   s2 = s1->Normalize();
   Console::Write( "B1) Is s2 normalized to the default form (Form C)?: " );
   Console::WriteLine( s2->IsNormalized() );
   Show( "s2", s2 );
   Console::WriteLine();
   s2 = s1->Normalize( NormalizationForm::FormC );
   Console::Write( "B2) Is s2 normalized to Form C?: " );
   Console::WriteLine( s2->IsNormalized( NormalizationForm::FormC ) );
   Show( "s2", s2 );
   Console::WriteLine();
   s2 = s1->Normalize( NormalizationForm::FormD );
   Console::Write( "B3) Is s2 normalized to Form D?: " );
   Console::WriteLine( s2->IsNormalized( NormalizationForm::FormD ) );
   Show( "s2", s2 );
   Console::WriteLine();
   s2 = s1->Normalize( NormalizationForm::FormKC );
   Console::Write( "B4) Is s2 normalized to Form KC?: " );
   Console::WriteLine( s2->IsNormalized( NormalizationForm::FormKC ) );
   Show( "s2", s2 );
   Console::WriteLine();
   s2 = s1->Normalize( NormalizationForm::FormKD );
   Console::Write( "B5) Is s2 normalized to Form KD?: " );
   Console::WriteLine( s2->IsNormalized( NormalizationForm::FormKD ) );
   Show( "s2", s2 );
   Console::WriteLine();
}

/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/

using System;
using System.Text;

class Example
{
    public static void Main()
    {
       // Character c; combining characters acute and cedilla; character 3/4
       string s1 = new String( new char[] {'\u0063', '\u0301', '\u0327', '\u00BE'});
       string s2 = null;
       string divider = new String('-', 80);
       divider = String.Concat(Environment.NewLine, divider, Environment.NewLine);

       Show("s1", s1);
       Console.WriteLine();
       Console.WriteLine("U+0063 = LATIN SMALL LETTER C");
       Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT");
       Console.WriteLine("U+0327 = COMBINING CEDILLA");
       Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS");
       Console.WriteLine(divider);

       Console.WriteLine("A1) Is s1 normalized to the default form (Form C)?: {0}",
                                    s1.IsNormalized());
       Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}",
                                    s1.IsNormalized(NormalizationForm.FormC));
       Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}",
                                    s1.IsNormalized(NormalizationForm.FormD));
       Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}",
                                    s1.IsNormalized(NormalizationForm.FormKC));
       Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}",
                                    s1.IsNormalized(NormalizationForm.FormKD));

       Console.WriteLine(divider);

       Console.WriteLine("Set string s2 to each normalized form of string s1.");
       Console.WriteLine();
       Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE");
       Console.WriteLine("U+0033 = DIGIT THREE");
       Console.WriteLine("U+2044 = FRACTION SLASH");
       Console.WriteLine("U+0034 = DIGIT FOUR");
       Console.WriteLine(divider);

       s2 = s1.Normalize();
       Console.Write("B1) Is s2 normalized to the default form (Form C)?: ");
       Console.WriteLine(s2.IsNormalized());
       Show("s2", s2);
       Console.WriteLine();

       s2 = s1.Normalize(NormalizationForm.FormC);
       Console.Write("B2) Is s2 normalized to Form C?: ");
       Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC));
       Show("s2", s2);
       Console.WriteLine();

       s2 = s1.Normalize(NormalizationForm.FormD);
       Console.Write("B3) Is s2 normalized to Form D?: ");
       Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD));
       Show("s2", s2);
       Console.WriteLine();

       s2 = s1.Normalize(NormalizationForm.FormKC);
       Console.Write("B4) Is s2 normalized to Form KC?: ");
       Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC));
       Show("s2", s2);
       Console.WriteLine();

       s2 = s1.Normalize(NormalizationForm.FormKD);
       Console.Write("B5) Is s2 normalized to Form KD?: ");
       Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD));
       Show("s2", s2);
       Console.WriteLine();
    }

    private static void Show(string title, string s)
    {
       Console.Write("Characters in string {0} = ", title);
       foreach(short x in s) {
           Console.Write("{0:X4} ", x);
       }
       Console.WriteLine();
    }
}
/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/

open System
open System.Text

let show title (s: string) =
    printf $"Characters in string %s{title} = "
    for x in s do
        printf $"{int16 x:X4} "
    printfn ""


[<EntryPoint>]
let main _ =
    // Character c; combining characters acute and cedilla; character 3/4
    let s1 = String [| '\u0063'; '\u0301'; '\u0327'; '\u00BE' |]
    let divider = String('-', 80)
    let divider = String.Concat(Environment.NewLine, divider, Environment.NewLine)

    show "s1" s1
    printfn "\nU+0063 = LATIN SMALL LETTER C"
    printfn "U+0301 = COMBINING ACUTE ACCENT"
    printfn "U+0327 = COMBINING CEDILLA"
    printfn "U+00BE = VULGAR FRACTION THREE QUARTERS"
    printfn $"{divider}"

    printfn $"A1) Is s1 normalized to the default form (Form C)?: {s1.IsNormalized()}"
    printfn $"A2) Is s1 normalized to Form C?:  {s1.IsNormalized NormalizationForm.FormC}"
    printfn $"A3) Is s1 normalized to Form D?:  {s1.IsNormalized NormalizationForm.FormD}"
    printfn $"A4) Is s1 normalized to Form KC?: {s1.IsNormalized NormalizationForm.FormKC}"
    printfn $"A5) Is s1 normalized to Form KD?: {s1.IsNormalized NormalizationForm.FormKD}"

    printfn $"{divider}"

    printfn "Set string s2 to each normalized form of string s1.\n"
    printfn "U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE"
    printfn"U+0033 = DIGIT THREE"
    printfn"U+2044 = FRACTION SLASH"
    printfn"U+0034 = DIGIT FOUR"
    printfn $"{divider}"
 
    let s2 = s1.Normalize()
    printf "B1) Is s2 normalized to the default form (Form C)?: "
    printfn $"{s2.IsNormalized()}"
    show "s2" s2
    printfn ""

    let s2 = s1.Normalize NormalizationForm.FormC
    printf "B2) Is s2 normalized to Form C?: "
    printfn $"{s2.IsNormalized NormalizationForm.FormC}"
    show "s2" s2
    printfn ""

    let s2 = s1.Normalize NormalizationForm.FormD
    printf "B3) Is s2 normalized to Form D?: "
    printfn $"{s2.IsNormalized NormalizationForm.FormD}"
    show "s2" s2
    printfn ""

    let s2 = s1.Normalize(NormalizationForm.FormKC)
    printf "B4) Is s2 normalized to Form KC?: "
    printfn $"{s2.IsNormalized NormalizationForm.FormKC}"
    show "s2" s2
    printfn ""

    let s2 = s1.Normalize(NormalizationForm.FormKD)
    printf "B5) Is s2 normalized to Form KD?: "
    printfn $"{s2.IsNormalized NormalizationForm.FormKD}"
    show "s2" s2
    0

(*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*)

Imports System.Text

Class Example
   Public Shared Sub Main()
      ' Character c; combining characters acute and cedilla; character 3/4
      Dim s1 = New [String](New Char() {ChrW(&H0063), ChrW(&H0301), ChrW(&H0327), ChrW(&H00BE)})
      Dim s2 As String = Nothing
      Dim divider = New [String]("-"c, 80)
      divider = [String].Concat(Environment.NewLine, divider, Environment.NewLine)
      
      Show("s1", s1)
      Console.WriteLine()
      Console.WriteLine("U+0063 = LATIN SMALL LETTER C")
      Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT")
      Console.WriteLine("U+0327 = COMBINING CEDILLA")
      Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS")

      Console.WriteLine(divider)
      
      Console.WriteLine("A1) Is s1 normalized to the default form (Form C)?: {0}", s1.IsNormalized())
      Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", s1.IsNormalized(NormalizationForm.FormC))
      Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", s1.IsNormalized(NormalizationForm.FormD))
      Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", s1.IsNormalized(NormalizationForm.FormKC))
      Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", s1.IsNormalized(NormalizationForm.FormKD))
      
      Console.WriteLine(divider)
      
      Console.WriteLine("Set string s2 to each normalized form of string s1.")
      Console.WriteLine()
      Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE")
      Console.WriteLine("U+0033 = DIGIT THREE")
      Console.WriteLine("U+2044 = FRACTION SLASH")
      Console.WriteLine("U+0034 = DIGIT FOUR")
      Console.WriteLine(divider)
      
      s2 = s1.Normalize()
      Console.Write("B1) Is s2 normalized to the default form (Form C)?: ")
      Console.WriteLine(s2.IsNormalized())
      Show("s2", s2)
      Console.WriteLine()
      
      s2 = s1.Normalize(NormalizationForm.FormC)
      Console.Write("B2) Is s2 normalized to Form C?: ")
      Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC))
      Show("s2", s2)
      Console.WriteLine()
      
      s2 = s1.Normalize(NormalizationForm.FormD)
      Console.Write("B3) Is s2 normalized to Form D?: ")
      Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD))
      Show("s2", s2)
      Console.WriteLine()
      
      s2 = s1.Normalize(NormalizationForm.FormKC)
      Console.Write("B4) Is s2 normalized to Form KC?: ")
      Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC))
      Show("s2", s2)
      Console.WriteLine()
      
      s2 = s1.Normalize(NormalizationForm.FormKD)
      Console.Write("B5) Is s2 normalized to Form KD?: ")
      Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD))
      Show("s2", s2)
      Console.WriteLine()
   End Sub 
   
   Private Shared Sub Show(title As String, s As String)
      Console.Write("Characters in string {0} = ", title)
      For Each x As Char In s
         Console.Write("{0:X4} ", AscW(x))
      Next 
      Console.WriteLine()
   End Sub 
End Class 
'This example produces the following results:
'
'Characters in string s1 = 0063 0301 0327 00BE
'
'U+0063 = LATIN SMALL LETTER C
'U+0301 = COMBINING ACUTE ACCENT
'U+0327 = COMBINING CEDILLA
'U+00BE = VULGAR FRACTION THREE QUARTERS
'
'--------------------------------------------------------------------------------
'
'A1) Is s1 normalized to the default form (Form C)?: False
'A2) Is s1 normalized to Form C?:  False
'A3) Is s1 normalized to Form D?:  False
'A4) Is s1 normalized to Form KC?: False
'A5) Is s1 normalized to Form KD?: False
'
'--------------------------------------------------------------------------------
'
'Set string s2 to each normalized form of string s1.
'
'U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
'U+0033 = DIGIT THREE
'U+2044 = FRACTION SLASH
'U+0034 = DIGIT FOUR
'
'--------------------------------------------------------------------------------
'
'B1) Is s2 normalized to the default form (Form C)?: True
'Characters in string s2 = 1E09 00BE
'
'B2) Is s2 normalized to Form C?: True
'Characters in string s2 = 1E09 00BE
'
'B3) Is s2 normalized to Form D?: True
'Characters in string s2 = 0063 0327 0301 00BE
'
'B4) Is s2 normalized to Form KC?: True
'Characters in string s2 = 1E09 0033 2044 0034
'
'B5) Is s2 normalized to Form KD?: True
'Characters in string s2 = 0063 0327 0301 0033 2044 0034
'

Normalize()

Source:: String.cs

Source:: String.cs

Source:: String.cs

Returns a new string whose textual value is the same as this string, but whose binary representation is in Unicode normalization form C.

public:
 System::String ^ Normalize();

public string Normalize ();

member this.Normalize : unit -> string

Public Function Normalize () As String

Returns

String

A new, normalized string whose textual value is the same as this string, but whose binary representation is in normalization form C.

Exceptions

ArgumentException

The current instance contains invalid Unicode characters.

Remarks

Some Unicode characters have multiple equivalent binary representations consisting of sets of combining and/or composite Unicode characters. For example, any of the following code points can represent the letter "ắ":

U+1EAF
U+0103 U+0301
U+0061 U+0306 U+0301

The existence of multiple representations for a single character complicates searching, sorting, matching, and other operations.

The Unicode standard defines a process called normalization that returns one binary representation when given any of the equivalent binary representations of a character. Normalization can be performed with several algorithms, called normalization forms, that obey different rules. .NET supports the four normalization forms (C, D, KC, and KD) that are defined by the Unicode standard. When two strings are represented in the same normalization form, they can be compared by using ordinal comparison.

To normalize and compare two strings, do the following:

Obtain the strings to be compared from an input source, such as a file or a user input device.
Call the Normalize() method to normalize the strings to normalization form C.
To compare two strings, call a method that supports ordinal string comparison, such as the Compare(String, String, StringComparison) method, and supply a value of StringComparison.Ordinal or StringComparison.OrdinalIgnoreCase as the StringComparison argument. To sort an array of normalized strings, pass a comparer value of StringComparer.Ordinal or StringComparer.OrdinalIgnoreCase to an appropriate overload of Array.Sort.
Emit the strings in the sorted output based on the order indicated by the previous step.

For a description of supported Unicode normalization forms, see System.Text.NormalizationForm.

Notes to Callers

The IsNormalized method returns false as soon as it encounters the first non-normalized character in a string. Therefore, if a string contains non-normalized characters followed by invalid Unicode characters, the Normalize method will throw an ArgumentException although IsNormalized returns false.

Applies to

Normalize(NormalizationForm)

Source:: String.cs

Source:: String.cs

Source:: String.cs

Returns a new string whose textual value is the same as this string, but whose binary representation is in the specified Unicode normalization form.

public:
 System::String ^ Normalize(System::Text::NormalizationForm normalizationForm);

public string Normalize (System.Text.NormalizationForm normalizationForm);

member this.Normalize : System.Text.NormalizationForm -> string

Public Function Normalize (normalizationForm As NormalizationForm) As String

Parameters

normalizationForm: NormalizationForm

A Unicode normalization form.

Returns

String

A new string whose textual value is the same as this string, but whose binary representation is in the normalization form specified by the normalizationForm parameter.

Exceptions

ArgumentException

The current instance contains invalid Unicode characters.

Remarks

Some Unicode characters have multiple equivalent binary representations consisting of sets of combining and/or composite Unicode characters. The existence of multiple representations for a single character complicates searching, sorting, matching, and other operations.

To normalize and compare two strings, do the following:

Obtain the strings to be compared from an input source, such as a file or a user input device.
Call the Normalize(NormalizationForm) method to normalize the strings to a specified normalization form.
To compare two strings, call a method that supports ordinal string comparison, such as the Compare(String, String, StringComparison) method, and supply a value of StringComparison.Ordinal or StringComparison.OrdinalIgnoreCase as the StringComparison argument. To sort an array of normalized strings, pass a comparer value of StringComparer.Ordinal or StringComparer.OrdinalIgnoreCase to an appropriate overload of Array.Sort.
Emit the strings in the sorted output based on the order indicated by the previous step.

For a description of supported Unicode normalization forms, see System.Text.NormalizationForm.

Notes to Callers

The IsNormalized method returns false as soon as it encounters the first non-normalized character in a string. Therefore, if a string contains non-normalized characters followed by invalid Unicode characters, the Normalize method may throw an ArgumentException although IsNormalized returns false.

Applies to

Share via

String.Normalize Method

Definition

Overloads

Examples

Normalize()

Returns

Exceptions

Remarks

Notes to Callers

See also

Applies to

Normalize(NormalizationForm)

Parameters

Returns

Exceptions

Remarks

Notes to Callers

See also

Applies to

Additional resources